1Jn 2:1 My little children, these things write I unto you, that ye sin not. And if any man sin, we have an advocate with the Father, Jesus Christ the righteous.
Heb 13:5 Let your conversation be without covetousness; and be content with such things as ye have: for he hath said, I will never leave thee, nor forsake thee.
Mat 22:14 For many are called, but few are chosen.
1Co 1:26 For ye see your calling, brethren, how that not many wise men after the flesh, not many mighty, not many noble, are called.
Rom 11:29 For the gifts and calling of God are without repentance.
Many are called, but few are chosen, and when God calls a person He will work with that person to get them to the truth, and when they are saved then they have the Spirit, which Jesus will never leave or forsake them.
All sin can be forgiven even if you live in sin for a year, but God will not give up on you for the gifts and calling of God, are without repentance.
Isa 59:2 But your iniquities have separated between you and your God, and your sins have hid his face from you, that he will not hear.
2Ti 2:19 Nevertheless the foundation of God standeth sure, having this seal, The Lord knoweth them that are his. And, Let every one that nameth the name of Christ depart from iniquity.
Heb 10:26 For if we sin wilfully after that we have received the knowledge of the truth, there remaineth no more sacrifice for sins,
Heb 10:27 But a certain fearful looking for of judgment and fiery indignation, which shall devour the adversaries.
But we cannot hold unto sin and be right with God, for then the blood of Jesus cannot wash it away.
So if we do sin we have to have the right attitude that we cannot hold unto sin and have salvation.
2Ti 3:4 lovers of pleasures more than lovers of God;
2Ti 3:5 Having a form of godliness, but denying the power thereof: from such turn away.
2Ti 3:6 For of this sort are they which creep into houses, and lead captive silly women laden with sins, led away with divers lusts,
2Ti 3:7 Ever learning, and never able to come to the knowledge of the truth.
Some people hold unto sin and believe they still have salvation, and are lovers of pleasures more than lovers of God, which He said turn away from those people.
1Co 5:11 But now I have written unto you not to keep company, if any man that is called a brother be a fornicator, or covetous, or an idolater, or a railer, or a drunkard, or an extortioner; with such an one no not to eat.
1Co 5:12 For what have I to do to judge them also that are without? do not ye judge them that are within?
1Co 5:13 But them that are without God judgeth. Therefore put away from among yourselves that wicked person.
But these people can still be forgiven but they are not right when they hold unto sin, and some hold unto sin and believe they have salvation.